WASHINGTON — You might say the Janet Jackson moment of President Bush’s inaugural festivities came Tuesday at a youth concert with hundreds of preteen Hilary Duff fans in the audience.

No nudity was involved, but the Vince Neil-style profanity probably didn’t win rock band Fuel any fans at the Federal Communications Commission, nor from the parents at the concert. Now the Pennsylvania band is just hoping the concert, “America’s Future Rocks Today,” wasn’t aired live.

Borrowing a word from Motley Crue’s Neil, the lead singer of Fuel proclaimed, “Welcome to the greatest ----ing country in the world.” Brett Scallions followed with a quick apology of “excuse my language.”

The FCC is investigating Neil’s wish to band mate Tommy Lee for a “Happy ----ing New Year,” which aired live on NBC on New Year’s Eve.

The outburst was one of the most interesting moments of Tuesday’s concert, hosted by Bush twins Jenna and Barbara, who were in the audience but did not come on stage.

Duff was the headliner at the half-full D.C. Armory concert, which paid tribute to youth volunteerism and community service. Duff, who performed in a black sequin top, rolled-up jeans and sneakers, warmed up the crowd for the president and first lady Laura Bush.

“My call to you all is that as you enjoy the great freedoms of America and as you enjoy yourself at this inauguration, I hope you take away the lesson of helping somebody in need,” said Bush, who arrived toward the end of the concert after Scallions’ remark. “And when you do, it will not only make our country a better place, it will lift up your own spirit.”

Other performers included 2003 “American Idol” winner Ruben Studdard, pop singer JoJo and the band 3 Doors Down. Also appearing were former football player Jason Sehorn; actor Stephen Baldwin, who rode a skateboard onto the stage; and “Access Hollywood’s” Nancy O’Dell, who co-hosts the entertainment show with Billy Bush, whose father, Jonathan, is the brother of former President George H.W. Bush.

A crowd favorite, besides Duff, was singer-songwriter Ryan Cabrera, a Dallas native who whipped up the audience with his jams on the guitar and the drums. Cabrera, 20, said his last trip to Washington was in the seventh grade on a field trip. “I lost my contact lens in the Capitol,” he told the audience, urging them to keep an eye out for it.